This invention relates to thermostatically controlled apparatus and more particularly to such control apparatus for controlling the automatic operation of the heating system and a cooling system in response to the temperature of a monitored environment.
Essentially, there are many facilities which can utilize both air conditioning and heating units for all seasons. Such units may be wall mounted, floor mounted or window mounted units. Even though such units may have their own thermostat controls, it would be desirable to control all such units from a single thermostat unit.
For examples of thermostatically controlled outlets which relate to the separate control of heating and air conditioning systems, reference is made to U.S. Pat. No. 4,687,050 issued to Kalman Podlipnik, the inventor herein, on Aug. 18, 1987 and entitled "Dual Thermostat Controlled Outlets". In that system there is shown a housing which contains two thermostats interviewed so as to enable one thermostat to control the heating operation and the other thermostat to control a cooling operation. As seen in that patent, a housing contains AC power receptacles which are coupled, respectively, to the thermostats to enable a separate heating system to be activated when needed and to enable an air conditioning unit or a fan to be activated during intervals when heating is not required. In any event, there are many references which operate as thermostatic units to afford dual control of both heating and air conditioning systems.
The present invention utilizes a pair of mercury switches or similar devices which are connected to a single bimetallic element, which element is adjusted by an indicator arm and is adapted to sense the temperature of the space or room within preselected temperature ranges. A pair of mercury switches are associated with the thermostat and are operable for controlling the operation of the heating system and the cooling system while providing automatic changeover between heating and cooling. In this manner the mercury switches are interwired so as one mercury switch enables the controlling of heat via the heating system and the other mercury switch controls the cooling operation.
As will be explained, one mercury switch can energize a first load and the other mercury switch can energize a second load. Due to the interconnection and positioning of the switches, when either mercury switch is operable to energize its respective load, such as the heating or air conditioning unit, the other switch cannot function. It is a main object of the present invention to maintain the temperature of the environment at a predetermined temperature within a specified temperature range, which range is purely a function of the setting and the offset between the first and second switches.